With this construction, the cover pit is barely visible because it is completely below the water. This construction is also very suitable for swimming pools with an overflow gutter. With pools having a skimmer, the roller system should, if possible, be positioned on the skimmer side so that, in the case of an outdoor pool, the coarse contamination is transported directly in front of the skimmer.
| Construction: | Roller system let into the wall of the pool with a front panel. Water level is below the top of the shaft. Because the water level is above the top of the pit, guide rollers are built into the cover pit. |
| Installation: | Only for new pools |
| Maximum size: | 25 m x 50 m (larger sizes depending on pool shape) |
| Drive unit in separate motor pit: | Drive unit mounted on the shaft, or chain drive |
| Drive unit without motor pit: | Not recommended |
| Cover slats: | Standard slats 60 mm wide and 14 mm thick |
| Guidelines: | Installation approved only for private pools |